Senior Backend Engineer, International Eng

Department: Engineering

Location: Kraków, Poland

Employment Type: FullTime

🚀 Join the Future of Commerce with Whatnot!

Whatnot is the largest live shopping platform in North America and Europe to buy, sell, and discover the things you love. Whether it's trading cards, fashion, electronics, or live plants, our sellers are building real businesses across hundreds of categories. We're building live commerce at a scale that's never been done in the West, and there's no playbook to copy. The people here are shaping how an entirely new industry develops.

As a remote co-located team, we're inspired by our values and anchored in hubs across the US, UK, Ireland, Poland, Germany, and Australia. We move fast, stay close to our users, and focus on the work that drives the most impact.

We're one of the fastest growing marketplaces and were recently named the #1 Best Startup Employer in America by Forbes. Check out the latest Whatnot updates on our news and engineering blogs and join us as we enable anyone to turn their passion into a business and bring people together through commerce.

💻 Role 

We're looking for a Senior Backend Engineer to join our International Engineering team based in Poland. You'll work alongside a small, high-impact team of engineers across Poland and the US, partnering closely with product, operations, payments, logistics, and platform teams to solve the complex challenges of scaling a global marketplace, with an initial focus on Germany, France, and the UK.

International Engineering offers a unique combination of technical complexity and business impact. Every new market introduces different payment methods, tax requirements, shipping constraints, consumer protections, and operational challenges. In this role, you'll build the foundational systems that power Whatnot's international expansion, owning critical infrastructure while working closely with senior leadership to shape the architecture of a rapidly growing global marketplace.

The International Engineering team is responsible for the operational and transactional systems that enable Whatnot to scale globally, including:

• Cross-border transaction infrastructure

• Tax and regulatory compliance

• International post-purchase experiences

• Marketplace operational tooling and automation

As a Senior Backend Engineer, you'll design and build highly scalable distributed systems that support millions of transactions across multiple countries and regulatory environments. Your work will span core backend infrastructure and product-facing systems that directly improve buyer trust and seller success.

👋 About You

Required

• 5+ years of professional software engineering experience

• Strong backend engineering experience in distributed systems or large-scale platforms

• Experience designing, operating, and scaling reliable production services

• Strong proficiency in Python or Go.

• Experience working with relational databases and event-driven architectures

• Ability to drive projects independently from ambiguous problem statements to production launch

• Excellent communication skills and ability to collaborate across engineering, product, operations, and business stakeholders

Preferred

• Experience with payments, fintech, e-commerce, logistics, marketplace platforms, or compliance systems

• Experience building operational platforms, workflow systems, or transaction processing infrastructure

• Experience working in rapidly growing product organizations

💛 EOE

Whatnot is proud to be an Equal Opportunity Employer. We value diversity, and we do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, parental status, disability status, or any other status protected by local law. We believe that our work is better and our company culture is improved when we encourage, support, and respect the different skills and experiences represented within our workforce.